Jeepspeed Style with Coilovers and Long-Arms

[Goatman]

Aren't regular lift coils in the 225-250lb/in neighborhood? So using that 250 as the main spring should be pretty good, or 300 would be a fair amount stiffer.

The two springs combined give a primary rate of 136 lb/in, softer than normal XJ springs, and then they transition to the bottom 300 lb/in spring. So the rates are really 136 and then 300. A longer spring with more coils softens the rate, which is what happens when the two springs are stacked together. For example, two 200 lb springs stacked together would give a rate of 100 lbs/in.

 

[Phil]

Sorry Richard, yes I'm quite familiar with spring theory. (Rate A * Rate B)/(Rate A + Rate B)

What I meant was, isn't, say, an RE ZJ 4.5" or a Skyjacker 8" around 225 lb/in? So once he hits the rate stop, he's got a similar setup to what is known to work well in an XJ.

 

[Goatman]

Sorry Richard, yes I'm quite familiar with spring theory. (Rate A * Rate B)/(Rate A + Rate B)

What I meant was, isn't, say, an RE ZJ 4.5" or a Skyjacker 8" around 225 lb/in? So once he hits the rate stop, he's got a similar setup to what is known to work well in an XJ.

I wondered.........


Yes, total spring force at full compression is similar. Comparing 5" of uptravel, a 225 lb spring would have 1125 lb of spring force at full compression. A 250/300 C/O with the transition collar set at 2" would have 1172 lb of spring force at full compression. Of course, with the 14" travel shock if you used 6" of up travel the spring force would increase to 1472 lb at full compression, and 7" would increase it to 1772 lb. This all means a smoother ride over the small stuff but more bottoming resistance. I know you know this, just discussing.

Now, figuring the same thing with air shocks, where the spring rate climbs exponentialy, you can have spring force at bottoming over 20,000 lbs.........but that's another subject.

 

[Loose_Nuts_Enterprises]

According to RE, the 4.5" inch springs have a spring rate of 185 lb/in. but after plugging the specs into a calculator, I came up with 212 lb/in.

 

[Goatman]

According to RE, the 4.5" inch springs have a spring rate of 185 lb/in. but after plugging the specs into a calculator, I came up with 212 lb/in.

I'd believe the 212.